Hypoxia, a decrease in oxygen tension occurring in pathological tissues, has a profound
effect on macrophage functions. Here, we provide the first evidence that hypoxia inhibits
CCR5 chemokine receptor expression in mouse macrophages. CCR5 was constitutively
expressed in macrophages and upregulated by IFNγ. Hypoxia downregulated both
constitutive and IFNγ-induced CCR5 mRNA and protein. Reoxygenation of hypoxic cells
reverted CCR5 inhibition. CCR5 upregulation by IL-10, LPS, and IL-4 was also antagonized …